Door operating mechanism

ABSTRACT

An operating mechanism for a sliding door in which a linear motion device, such as a dual acting cylinder having a rod extending from each end of the device and carrying a pulley thereon, is mounted on a fixed base to one side of the door, a flexible strand passes around both pulleys and has both ends fixed to the base. The door carries a strand clamp whereby the door is attached to the flexible strand. Actuation of the linear motion device will cause movement of the door from the closed to the open position or vice versa, such movement being twice that of the linear motion device.

Unlted States Patent 1 1 1111 3,863,390 Sawdai Feb. 4, 1975 [5 DOOR OPERATING MECHANISM 3,553,890 1/1971 Stretton 49/360 x Inventor: J p sawdai, ROSS pq 3,720,020 3/1973 Bolllnger 49/362 Allegheny Primary Examiner]. Karl Bell [73] Assignee: United States Steel Corporation, Attorney, Agent, or Firm-Ralph H. Dougherty Pittsburgh, Pa. 221 Filed: Mar. 1 1973 55 h T 11 operating mec anism or a s i ing door in which a [21] Appl 341826 linear motion device, such as a dual acting cylinder having a rod extending from each end of the device [52] U.S. Cl. 49/360, 49/362 1 and y g a pu ey th n. s m unted on a fixed [51] Int. Cl. E05f 15/06, E051 15/14 base to Side Of the r, a fl xi le tr nd passes [58] Field of Search 49/360, 362, 118, 349, around both p y and has both e f ed to the 9/352; 74/8911, 89.12, 89.2, 89.21, 89.22; ase. The door carries a strand clamp whereby the 92/137; 91/411 R door is attached to the flexible strand. Actuation of the linear motion device will cause movement of the [56] Refe scit d door from the closed to the open position or vice UNITED STATES PATENTS versa, such movement being twice that of the linear 2,425,016 8/1947- Weaver 49/118 x mono devlce' 2,480,527 8/1949 Wachter 49/360 X 7 Claims, 3 Drawing Figures PATENTED FEB 4 SHEET 10F 2 FIG. 2.

PATENTEDFEB 41% 3,863,390

SHEET 2 OF 2 FIG. 3.

Furnace doors and hood doors are subject to a high degree of heat which causes door warpage. A door operating mechanism must be capable of operating the door regardless of the amount of or type of warpage. Further, in case of drive failure, it must be possible to operate the door by'some other means.

At present, such doors are normally driven by a chain and sprocket whereby the door is attached to the chain and a driving device turns one of the sprockets, thus moving the chain and with it the door. The chain and sprocket component must be mounted in such a position that they are out of the door opening, or doorway,.

and away from the heat and flameof the furnace when the door is open. These requirements limit the location of the chain and sprocket components to a position above the door opening where they must be in a protective enclosure. It is also necessary to provide door stops in either direction so the device connecting the door to the chain does not run into the sprocket, damaging it.

It is the primary object of the present invention to provide a door operating apparatus for a laterallymovable door using simple, readily available components, which moves a door from a first position to a second position with a positive action.

It is also an object of the invention to provide a door operating mechanism which will tolerate a great amount of warpage in the door.

It is another object of the invention to provide a door operating mechanism which is easy to service without removing the door.

It is another object of the invention to provide a door operating mechanism that is easy to disengage from a door.

It is a further object of the invention to provide a door operating mechanism which moves the door a predetermined distance when the mechanism is actuated, thus obviating the need for door stops.

It is a still further object of the invention to provide a door operating mechanism for'use in a high heat environment which requires no further shielding or protection other than the door itself.

These and other objects will become more readily apparent by reference to the following detailed description and the appended drawings in which:

FIG. I is a schematic front elevational view of a pair pulley or-wheel 18 for rotation on each end of the rod exterior to the cylinder. The term pulley as used herein will be taken to mean pulley, wheel, sheave, sprocket, etc., i.e., any rotatable device over which or around which a flexible strand can pass. A flexible strand 22 is fastened at one end to base 12 at point 24A, passes over pulley 18A and 18B and is fastened at the other end to base 12 at point 248. Strand clamp 26, in this case a cable clamp, is attached to door 14 by any convenient means. A quick disconnect pin 28 can be employed for ease in removing the operating mechanism from the door when desired.

Alternatively, the linear motion device can be either an electrically, hydraulically, or pneumatically actuatedcylinder, a rack and pinion, or even a screw jack having a pulley-carrying rod attached thereto, or a pair of substantially co-linear rods, one connected to each end of the rack or screw. The flexible strand can be, but is not limited to, a cable or a chain.

The embodiment of FIG. 3 shows a chain 32 fastened to base 12 and passing around sprockets 38A and 388 which are rotatably mounted on shaft 36. Door 14 is attached to flexible chain 32 by clamp 26. The linear motion device which drives the door includes a rack 40 and pinion 42, which pinion is driven by a reversing motor 44.

In operation, when the cylinder 10 is actuated, the door 14, being attached to cable 22, will move twice the distance. of the cylinder stroke.

The limit of the cylinderstroke determines the limit of the door movement, thus no external door stops are needed. Since the cylinder 10 is mounted remote from the doorway 15, it is out of the way of intense heat and flame and thus protected therefrom. Further, as seen in FIG. 2, when the. door is open, the entire door openingmechanism is out of the opendoorway and thus is protected and in a position for servicing. Door warpage does not affect my mechanism because the strand 22 is flexible and any twist imparted by warpage of the door 14 to the cylinder rod 16 and pulleys 18 can readilybe tolerated. If there is a malfunction of the cylinder 10, the cable clamp 26 can be quickly released and the door can be. opened or closed by an overhead traveling crane by attaching a cable at the same point that my cable 22 is attached, or quick disconnect pin 28 can be of adjacent doors in the closed position, said doors having my improved door operating apparatus.

FIG. 2 is a schematic front elevational view similar to FIG. 1 with the doors in the open position.

FIG. 3 is a partial schematic front elevational view similar to FIG. 2, but on a larger scale and showing alternative embodiments.

As shown in the figures, a linear motion device, such as double-acting cylinder 10, is mounted on a fixed base 12 at one side of and out of the line of movement of door 14, which door opens and closes doorway 15. The cylindrical 10 has a double rod piston 16, and a released and thedoor can be moved by any mobile unit. I

It can readily be seen from the foregoing that l have invented an improved door operating apparatus which is simple and relatively inexpensive to construct, yet will move a door from a first or closed position to a second or open position or vice versa with a positive action, will tolerage warpage in a door, is easy to service and to disengagefrom a door, requires no door stops to prevent the door from moving too far and requires no additional devices to protect it from heat or flame when the door is installed on a high temperature furnace.

I claim: 1. Apparatus for opening'and closing a doorway comprising:

at least one door mounted for lateral sliding move-.

connecting means comprising a rigid rod adapted to be linearly driven by said linear motion device in the direction of said door movements, said rod having ends thereof exterior to said device;

a pulley journaled on each end of said rod; I

a flexible strand passing around both pulleys, both ends of said strand being fixed to the base upon which said linear motion device is mounted;

a strand clamp connecting said door and said strand, and means to actuate said linear motion device to cause movement of said door ina desired direction into or out of a doorway closing position.

2. Apparatus according to claim 1 wherein said linear motion device is a double-acting cylinder and the connected to said strand. 

1. Apparatus for opening and closing a doorway comprising: at least one door mounted for lateral sliding movement into and out of a doorway closing position; a fixed base adjacent and spaced from at least one side of said doorway; a linear motion device fixed to each said base; connecting means comprising a rigid rod adapted to be linearly driven by said linear motion device in the direction of said door movements, said rod having ends thereof exterior to said device; a pulley jOurnaled on each end of said rod; a flexible strand passing around both pulleys, both ends of said strand being fixed to the base upon which said linear motion device is mounted; a strand clamp connecting said door and said strand, and means to actuate said linear motion device to cause movement of said door in a desired direction into or out of a doorway closing position.
 2. Apparatus according to claim 1 wherein said linear motion device is a double-acting cylinder and the connecting means is a double rod slidably mounted therein.
 3. Apparatus according to claim 1 wherein said linear motion device is a rack and pinion.
 4. Apparatus according to claim 1 wherein said flexible strand is a cable.
 5. Apparatus according to claim 1 wherein said flexible strand is a chain.
 6. Apparatus according to claim 5 wherein said pulley is a sprocket.
 7. Apparatus according to claim 1 wherein said strand clamp is fixed to said door and releasably connected to said strand. 